Mighty Line Floor Marking Stop Modern Floor Signs. Mighty Line Stop Floor Signs are the best floor signs for telling traffic to stop inside of your facility. Mighty Line floor signs are great for industrial use. Mighty Line stop floor signs are heavy duty and industrial grade. A variety of locations are using this popular Mighty Line stop floor sign to keep their facility safe.  Mighty Line safety floor signs are a great floor marking tool. Mighty Line floor signs are perfect solutions for 5s facilities, lean operations, and for warehouse safety. Part Numbers STOPMODERN12 - 12' Stop Floor Sign STOPMODERN16 - 16' Stop Floor Sign STOPMODERN24 - 24' Stop Floor Sign Made in the USA